xref: /freebsd/sys/cam/ctl/ctl_backend.c (revision d184218c18d067f8fd47203f54ab02a7b2ed9b11)
1 /*-
2  * Copyright (c) 2003 Silicon Graphics International Corp.
3  * All rights reserved.
4  *
5  * Redistribution and use in source and binary forms, with or without
6  * modification, are permitted provided that the following conditions
7  * are met:
8  * 1. Redistributions of source code must retain the above copyright
9  *    notice, this list of conditions, and the following disclaimer,
10  *    without modification.
11  * 2. Redistributions in binary form must reproduce at minimum a disclaimer
12  *    substantially similar to the "NO WARRANTY" disclaimer below
13  *    ("Disclaimer") and any redistribution must be conditioned upon
14  *    including a substantially similar Disclaimer requirement for further
15  *    binary redistribution.
16  *
17  * NO WARRANTY
18  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
19  * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
20  * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTIBILITY AND FITNESS FOR
21  * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
22  * HOLDERS OR CONTRIBUTORS BE LIABLE FOR SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
23  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
24  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
25  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
26  * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING
27  * IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
28  * POSSIBILITY OF SUCH DAMAGES.
29  *
30  * $Id: //depot/users/kenm/FreeBSD-test2/sys/cam/ctl/ctl_backend.c#3 $
31  */
32 /*
33  * CTL backend driver registration routines
34  *
35  * Author: Ken Merry <ken@FreeBSD.org>
36  */
37 
38 #include <sys/cdefs.h>
39 __FBSDID("$FreeBSD$");
40 
41 #include <sys/param.h>
42 #include <sys/systm.h>
43 #include <sys/kernel.h>
44 #include <sys/types.h>
45 #include <sys/malloc.h>
46 #include <sys/lock.h>
47 #include <sys/mutex.h>
48 #include <sys/condvar.h>
49 #include <sys/queue.h>
50 #include <sys/sysctl.h>
51 
52 #include <cam/scsi/scsi_all.h>
53 #include <cam/scsi/scsi_da.h>
54 #include <cam/ctl/ctl_io.h>
55 #include <cam/ctl/ctl.h>
56 #include <cam/ctl/ctl_frontend.h>
57 #include <cam/ctl/ctl_backend.h>
58 #include <cam/ctl/ctl_frontend_internal.h>
59 #include <cam/ctl/ctl_ioctl.h>
60 #include <cam/ctl/ctl_ha.h>
61 #include <cam/ctl/ctl_private.h>
62 #include <cam/ctl/ctl_debug.h>
63 
64 extern struct ctl_softc *control_softc;
65 
66 int
67 ctl_backend_register(struct ctl_backend_driver *be)
68 {
69 	struct ctl_softc *ctl_softc;
70 	struct ctl_backend_driver *be_tmp;
71 
72 	ctl_softc = control_softc;
73 
74 	mtx_lock(&ctl_softc->ctl_lock);
75 	/*
76 	 * Sanity check, make sure this isn't a duplicate registration.
77 	 */
78 	STAILQ_FOREACH(be_tmp, &ctl_softc->be_list, links) {
79 		if (strcmp(be_tmp->name, be->name) == 0) {
80 			mtx_unlock(&ctl_softc->ctl_lock);
81 			return (-1);
82 		}
83 	}
84 	mtx_unlock(&ctl_softc->ctl_lock);
85 
86 	/*
87 	 * Call the backend's initialization routine.
88 	 */
89 	be->init();
90 
91 	mtx_lock(&ctl_softc->ctl_lock);
92 
93 	STAILQ_INSERT_TAIL(&ctl_softc->be_list, be, links);
94 
95 	ctl_softc->num_backends++;
96 
97 	/*
98 	 * Don't want to increment the usage count for internal consumers,
99 	 * we won't be able to unload otherwise.
100 	 */
101 	/* XXX KDM find a substitute for this? */
102 #if 0
103 	if ((be->flags & CTL_BE_FLAG_INTERNAL) == 0)
104 		MOD_INC_USE_COUNT;
105 #endif
106 
107 #ifdef CS_BE_CONFIG_MOVE_DONE_IS_NOT_USED
108 	be->config_move_done = ctl_config_move_done;
109 #endif
110 	/* XXX KDM fix this! */
111 	be->num_luns = 0;
112 #if 0
113 	atomic_set(&be->num_luns, 0);
114 #endif
115 
116 	mtx_unlock(&ctl_softc->ctl_lock);
117 
118 	return (0);
119 }
120 
121 int
122 ctl_backend_deregister(struct ctl_backend_driver *be)
123 {
124 	struct ctl_softc *ctl_softc;
125 
126 	ctl_softc = control_softc;
127 
128 	mtx_lock(&ctl_softc->ctl_lock);
129 
130 #if 0
131 	if (atomic_read(&be->num_luns) != 0) {
132 #endif
133 	/* XXX KDM fix this! */
134 	if (be->num_luns != 0) {
135 		mtx_unlock(&ctl_softc->ctl_lock);
136 		return (-1);
137 	}
138 
139 	STAILQ_REMOVE(&ctl_softc->be_list, be, ctl_backend_driver, links);
140 
141 	ctl_softc->num_backends--;
142 
143 	/* XXX KDM find a substitute for this? */
144 #if 0
145 	if ((be->flags & CTL_BE_FLAG_INTERNAL) == 0)
146 		MOD_DEC_USE_COUNT;
147 #endif
148 
149 	mtx_unlock(&ctl_softc->ctl_lock);
150 
151 	return (0);
152 }
153 
154 struct ctl_backend_driver *
155 ctl_backend_find(char *backend_name)
156 {
157 	struct ctl_softc *ctl_softc;
158 	struct ctl_backend_driver *be_tmp;
159 
160 	ctl_softc = control_softc;
161 
162 	mtx_lock(&ctl_softc->ctl_lock);
163 
164 	STAILQ_FOREACH(be_tmp, &ctl_softc->be_list, links) {
165 		if (strcmp(be_tmp->name, backend_name) == 0) {
166 			mtx_unlock(&ctl_softc->ctl_lock);
167 			return (be_tmp);
168 		}
169 	}
170 
171 	mtx_unlock(&ctl_softc->ctl_lock);
172 
173 	return (NULL);
174 }
175 
176 /*
177  * vim: ts=8
178  */
179